Elastic fluid power plant



May 30, 1944. F. B. SCHNEIDER 2,350,197

ELASTIC FLUID POWER PLANT Filed Feb. 28, 1941' Fig. I.

Inventor": Fred 18. Schneider;

b WW6:

His'Accorney.

Patented May 30, 1944 ELASTIC FLUID POWER PLANT Fred B. Schneider, Wesleyville, Pa., assignor to General Electric Company, a corporation of New York Application February 28, 1941, Serial No. 381,053

3 Claims.

The present invention relates to elastic fluid power plants including elastic fluid condensing apparatus for receiving and condensing exhaust fluid discharged from a turbine or like elastic fluid consumer and means for recuperating some of the heat contained in the exhaust fluid by bypassing part of the exhaust fluid with regard to the condensing apparatus. The invention is of particular significance with regard to locomotive power plants operating at high temperature and high pressure although it is not necessarily limited thereto.

The object of my invention is to provide an improved construction and arrangement whereby the deaeration of elastic fluid power plants and the recuperation of heat from exhaust fluid of turbines and like elastic fluid consumers is accomplished economically and efficiently.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing Fig. 1 illustrates an elastic fluid power plant embodying my invention, and Fig. 2 is an enlarged detail view in section of a part of Fig. 1.

The arrangement comprises a boiler or elas tic fluid generator III which has an inlet conduit I! for receiving operating medium such as water and a discharge conduit I2 for discharging elastic fluid such as steam to a turbine I3 or like consumer. The turbine I3 has an exhaust end I4 connected by a conduit I5 to a surface type condenser I6. This condenser may I be of any convenient type. In the present instance it is shown as including a plurality of cooling tubes or passages I! connected between an upper header l8 for conducting cooling medium to the tubes and a lower header I9 for receiving cooling medium from the tubes. The headers and cooling tubes are enclosed by an outer shell connected at its upper end to the exhaust conduit I5 for receiving fluid to be condensed and connected at its lower end to a conduit 2! for conducting condensate from the condenser to a hotwell 22.. Air and other non-condensables are removed from the condenser I6 and the hotwell 22 by means of an air removal apparatus such as an ejector 23 connected to the condenser I6 and the hotwell 22 by pipes 24 and 25 respectively. Condensate discharged into the hotwell is removed therefrom by means including a conduit 25 connected to the inlet of a boiler feed pump 27, which latter forces the condensate through the aforementioned conduit II into the boiler II].

In order to reduce the loss of heat transferred within the condenser apparatus IE to the cooling medium, which in many instances is III wasted, especially in the case of air-cooled surface type condensers and to reduce the size of the condenser surface, I provide means for by passing part of the exhaust fluid with regard to the condenser I6. This means according to my invention includes a conduit 28 with a valve 29.connected to receive exhaust fluid from the conduit I5 and to discharge such fluid into the hotwell.

The hotwell, as shown in 2. comprises a fabricated rectangular tank or casing 3%] which may be supported in the lower frame of a locomotive. The tank as has abottom 3| to which a pan 32 ecured. The left-hand portion of the pan .332 communicates with the interior of the tank 30. through a comparatively large opening 33 in the bottom 3!, and the right-hand portion of the pan 372. communicates with the interior of the tank 38 through a plurality of comparatively small openings 35. The outlet end of the. conduit 25 for bypassing part of the exhaust fluid with regard to the condenser is connected to the left-hand portion of the pan 32 and has outlet portion. directed substantially parallel to the bottom 3! of the tank 30 and in direction from the large opening 33 towards the small opening 34. The conduit 28 broadly constitutes a means for. injecting elastic fluid under pressure into the pan 32 in the general direction from the large openings towards the small openings. The pan 32 itself may be considered a conduit means connected to the bottom portion of the tank or casing 30 to receive condensate from the casing 30 through th large openings and to return such fluid through the small openings 36. In other words, such conduit means establishes communication between the openings 33 and 3d outside the casing.

During operation, elastic fluid conducted through the conduit 28 to the pan 32 causes circulation of condensate contained in the tank 30 through the large opening into the pan 32 and from the pan 32 through the small openings 34 into the tank 30. On its passage through the pan 32 the condensate is mixed with elastic fluid discharged from the conduit 2e and efiect-s condensation of the elastic fluid. The pan 32 thus constitutes a mixing chamber. Ordinarily the elastic fluid conducted to the pan 32 brings the condensate therein to boiling temperature and the boiling condensate discharged through the openings 34 into the tank 32] raises the temperature of the condensate therein preferably to the saturation point.

The pressure drop between the inlet of the conduit 23. or if the valve 29 is partly closed, between the outlet of this valve and the liquid level in the hotwell is substantially equal to the resistance consisting of impact loss within the pan or mixing chamber 32 and the entrance loss at the small openings 34. This resistance is so large that practically no elastic fluid escapes into the space above the liquid level in the hotwell. This is important as it avoids increasing back pressure in the condenser. At full load and high pressure drop between the exhaust conduit and the hotwell the large amount of sub-cooled condensate is heated to boiling temperature by a definite amount of elastic fluid conducted through the conduit 28. This may be controlled by properly adjusting the valve 29 in the conduit 28. During idling condiiton, the pressure drop between the exhaust conduit l5 and the hotwell 22 decreases, which decrease causes a corresponding reduction in the flow of elastic fluid through the conduit 28 into the mixing chamber 32. Preferably the arrangement is such that the reduced flow of heating fluid through the chamber 32 will be just sufficient to keep the hotwell condensate close to boiling point. Once the valv 29 is properly adjusted the entire arrangement works automatically as regards the change of flow through the bypass 28 with changes in the load.

The arrangement also includes means for indicating the liquid level in the hotwell 22. The level indicating means comprises a float 35 which in its lower end position projects into a cylindrical chamber 38 formed in the pan 32. The chamber 36 prevents the flow of fluid through the mixing chamber 32 from affecting the level indicator. The float 35 is connected to a rod 31 which is supported on a pivot 38 and carries an indicator 33. The cylindrical chamber 38 as viewed in Fig. 2 is located behind the fluid flow from the conduit 28 to the opening 34 and also behind the fluid flow from the large opening 33 through the mixing chamber to the small opening 34. Assuming that there is only one row of small openings 34, then the cylinder 36 is spaced from the plane through the centers of the outlet of the conduit 28 and the openings 33, 34 so that the cylinder 36 will not interfere with the circulation of fluid between the tank 30 and the mixing chamber 32.

The mixing chamber 32 is located below the liquid level in the hotwell formed by the tank 30 and broadly constitutes a bypass between spaced portions of the hotwell. The injection of elastic fluid into this bypass by means of the conduit 23 effects continuous circulation of condensate through the bypass.

The mixing chamber 32" and the bypass 28 broadly constitute a recuperator of heat energy contained in the fluid conducted to the condenser F arrangement. Part of the elastic fluid is bled to the recuperator and its heat content is transferred to the condensate in the hotwell. In this manner the fuel cost of the power plant may be materially reduced, for example from 1 to 4%.

The condenser proper 3 serves to condense part only of the elastic fluid and therefore may be made of smaller size than would be necessary were all the elastic fluid passed to the condenser l6.

With my elastic fluid condensing arrangement substantially complete deaeration of the condensate may be attained because the condensate surfaces located close to the air-removal apparatus are maintained at a temperature close to the saturation temperature. This facilitates the removal of air from the condensate which in turn improves the heat transfer and as regards the power plant as a whole results in better fuel economy. Complete deaeration at the same time decreases corrosion in the boiler, resulting in reduced maintenance cost.

Due to the better deaeration thus attained, it is possible to employ vacuum pumps in place of ejector pumps. Generally, in order to obtain a complete deaeration, it is necessary to bring the temperature of the condensate close to boiling. Heretofore in many cases elastic fluid jet air ejectors were used for the principal reason that their waste fluid should heat up the main condensate. As with my arrangement a great amount of heat is recuperated from the elastic? fluid to be condensed and the condensate in thei hotwell is maintained at or near saturation tem-, perature, it is no longer necessary to provide elastic fluid jet air ejectors. These ejectors may be readily replaced by vacuum pumps with better efflciency and ability to maintain higher vacuums.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Elastic fluid condensing arrangement comprising a hotwell having a bottom With spaced large and small openings, a mixing chamber connected to the spaced openings, and means including a conduit for conducting elastic fluid to the mixing chamber near the large opening to effect circulation of condensate from the hotwell through the large opening to the mixing chamber and from said chamber through the small opening into the hotwell.

2. Elastic fluid condensing arrangement including a hotwell having a bottom with a large opening and a plurality of small openings spaced from the large opening, a pan forming a mixing chamber being secured to the bottom and communicating with the hotwell through the openings, and means for heating the condensate in the hotwell including a valved conduit for conducting elastic fluid to the chamber to effect circulation of fluid from the hotwell through the large opening to the chamber and from the chamber through the small opening to the hotwell.

3. Elastic fluid condensing arrangement including a hotwell having a casing with a bottom portion with a large opening and a plurality of small openings spaced from the large opening, conduit means connected to the bottom portion to effect communication between the large opening and the small openings outside the casing, and means connected to the conduit means near the large opening for injecting elastic fluid under pressure into the conduit means in the direction from the large towards the small openings to create circulation of liquid from the casing through the large opening into the conduit means and from the conduitfmeans through the small openings into the casing to heat the condensate in the hotwell.

FRED B. SCHNEIDER. 

